Avaliação da qualidade microbiológica e produção de alface americana (Lactuca sativa L.) sob diferentes sistemas de irrigação, utilizando águas residuárias

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Chemical properties and enzyme activity in a sewage sludge-treated soil

A soil sample was taken from the top 0-20cm at Jaboticabal county, São Paulo State, Brazil, air dried, sieved to 5mm, and placed into pots (2700g per pot). Sewage sludge was air-dried, ground to 2mm, and thoroughly mixed to the top 0-10cm soil of each pot, which were irrigated with distilled water in a total volume equivalent to the last 30years average rainfall in the region. Sorghum was sowed 120days after sewage sludge incorporation and then the irrigation was made according to the plants' requirement. When the plants were about 10 cm high, they were thinned to two per pot. Soil samples (0-10, 10-20, and 20-30 cm depth) were obtained immediately after the incorporation of sewage sludge and at 30, 60, 120, and 170 days after, air dried, sieved to 2 mm and analyzed for organic matter (OM), pH (0,01 mol L-1 CaCl2), extractable P (resin), potassium (K), calcium (Ca), and magnesium (Mg), amylase and cellulase activity. Sewage sludge increased soil OM, pH, extractable phosphorus (P), K. Ca. amylase and cellulase activity, especially at the rate 16 t ha(-1). Organic matter, extractable P, K, Ca, Mg. and amylase activity were higher in the top 0-10cm, while pH was higher in the 20-30cm layer. Amylase activity was not affected by sampling depth. Organic matter, pH, extractable P. K, Ca, and Mg decreased during the experimental period. Amylase activity decreased until sorghum was sowed and increased afterwards. Cellulase activity increased until 90 days after sewage sludge application and then decreased. Sewage sludge used in the experiment should already contain some amylase activity or a substance that was a soil enzyme activator and also a substance that was an inhibitor of soil cellulase inhibitor. Sonic of the plant nutrients contained in sewage sludge, mainly P, did not migrate down the soil column. an indication that sewage sludge should be incorporated into the soil to improve nutrient bioavailability. Sorghum roots increased amylase activity but did not affect cellulase activity.

CERAMIC MATERIAL FROM SEWAGE SLUDGE AS SUPPORT MATERIAL SUPPLY WATER FILTRATION

This study shows a possibility of using municipal sewage sludge after thermal treatment in the production of a filtering material to water treatment. Due to the fast urbanization and implementation of high standards for effluent in many countries in recent years, the sewage sludge is being produced in an ever increasing amount. Therefore, the use of sludge is a suitable solution for the expected large quantity of sludge. Dehydration of sludge was performed by controlled heating at temperatures of 1100 degrees C, 850 degrees C, 650 degrees C, 350 degrees C for 3 hours. After thermal treatment the sludge was characterized by X-ray fluorescence, TG/DTG/DTA, residue solubilization and residue lixiviation tests. The aim of the present work was to observe, thought the characterization techniques, if the treated sewage sludge is or not adequate to be used as filter material to water treatment. It will be verified which treatment temperature of the sludge offer possibility to its use in water treatment without carrying pollutants in concentrations out of the standards.

Sintered Sewage Sludge As Support Material Used In Drinking Water Filtration

The processing of industry and domestic effluents in wastewater treatment plants reduces the amount of polluted material and forms reusable water and dehydrated sludge. the generation of hazardous municipal sludge can be decreased, as well as the impact on surface and underground water and the risk to human health. The aim this study is to verify the possibility to use sintered sewage sludge as support material after thermal treatment in the production of a filtering material to water supply systems. After thermal treatment the sewage sludge ash was characterized by X-ray fluorescence (XRF), leaching test and water solubilization. Dehydration of sludge was performed by controlled heating at temperatures of 180 degrees C, 350 degrees C, 600 degrees C, 850 degrees C and 1000 degrees C for 3 hours.

Influence of a Brazilian sewage outfall on the toxicity and contamination of adjacent sediments

The submarine sewage outfall of Santos (SSOS) is situated in the Santos Bay (São Paulo, Brazil) and is potentially a significant source of contaminants to the adjacent marine ecosystem. The present study aimed to assess the influence of SSOS on the sediment toxicity and contamination at Santos Bay. At the disposal site, sediments tended to be finer, organically richer and exhibited higher levels of surfactants and metals, sometimes exceeding the Threshold Effect Level values. The SSOS influence was more evident toward the East, where the sediments exhibited higher levels of TOC, total S and metals during the summer 2000 sampling campaign. Sediment toxicity to amphipods was consistently detected in four of the five stations studied. Amphipod survival tended to correlate negatively to Hg, total N and % mud. This work provides evidence that the SSOS discharge affects the quality of sediments from Santos Bay, and that control procedures are warranted. (c) 2005 Elsevier Ltd. All rights reserved.

Sewage sludge as nitrogen and phosphorus source for cane-plant and first ratoon crops

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of irrigation on wheat crop

O uso da irrigação na triticultura tem aumentado significativamente nos últimos anos no Brasil. Neste trabalho, objetivou-se avaliar a influência da irrigação na produtividade, na qualidade tecnológica da farinha e no sistema radicular do trigo. em experimento de campo no IAPAR, em Londrina, Paraná, a cultivar IPR 118 foi cultivada sob irrigação por aspersão convencional (Tratamento Irrigado) e sem irrigação (Tratamento Sequeiro). A produtividade foi determinada, colhendo-se três amostras de 25 m² por tratamento. Nestas mesmas amostras, procedeu-se à análise da qualidade tecnológica da farinha, sendo avaliada, entre outros parâmetros, a força de glúten (W). A avaliação do sistema radicular foi realizada após a colheita, no perfil de 0 a 45 cm de profundidade do solo, amostrando-se oito plantas em cada tratamento. O método da parede do perfil foi utilizado para determinar o número de raízes (NR) e o método do monólito para determinar a massa seca de raízes (MSR). A irrigação aumentou em três vezes a produtividade do trigo, porém diminuiu o W na farinha. Ainda assim, o valor de W encontrado no Tratamento Irrigado (249 10-4 J) foi suficiente para manter a classificação do trigo como tipo-pão, a mesma para o qual a cultivar IPR 118 é classificada. Os valores medidos de NR e a MSR foram iguais ou maiores no Tratamento Sequeiro.

Transition metal rates in latosol twice treated with sewage sludge

A reciclagem agrícola do lodo de esgoto tem provocado o acúmulo de metais pesados no solo e na água, podendo atingir níveis tóxicos e causar danos às plantas cultivadas, aos animais e ao homem, por meio da cadeia trófica. Neste intuito foi desenvolvido o presente experimento, em condições de campo, entre 2000 e 2002, onde foram avaliados os efeitos da aplicação de lodo de esgoto por dois anos, sobre a extração de metais de transição (essenciais e não) pelo extrator DTPA em um Latossolo Vermelho distrófico (LVd) de textura média. As concentrações dos elementos metálicos: Mn, Fe, Cd, Ni, Co, Pb e Cr não foram detectados pelo método da absorção atômica na solução obtida com o extrator DTPA. A aplicação de lodo de esgoto causou inicialmente pequena elevação no pH do solo, posteriormente a diminuição do mesmo, e manteve-se próximo ao original. Foi possível concluir que, com a aplicação consecutiva do lodo, os teores extraíveis de Fe e Mn nas amostras de solos aumentaram gradativamente nos dois anos agrícolas, com as doses do lodo de esgoto aplicado, época de amostragens, e foram superiores ao tratamento testemunha. O extrator apresentou capacidade restrita para avaliação da fitodisponibilidade dos metais pesados decorrentes das baixas concentrações nas amostras de solo.

Measurement systems of soil water matric potential and evaluation of soil moisture under different irrigation depths

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Seedlings production of Tabebuia heptaphylla in different substrates and levels of irrigation, in greenhouse conditions

The objective of this research was to evaluate the growth of Tabebuia heptaphylla seedlings in distinct substrates with different amounts of urban waste compost and the relation between this growth and irrigation. A completely randomized experimental design was used, with a factorial arrangement of 15 substrates and 2 irrigation levels. The substrates were composed by the combination of different materials: urban waste, tanned cattle manure, vermiculite, soil and the commercial form Plantmax (R). For the study of the seedlings development, the following characteristics were evaluated: plant height, stem diameter at soil level, number of leaves, above ground dry matter, root system dry matter, relation between plant height and stem base diameter, Dickson quality index and relation between plant height and above ground dry matter. Evaluations of plant height, stem diameter at soil level and number of leaves were made at 75, 90, 105, 120, 135 and 150 days after sowing. According to the results, it was concluded that urban waste compost does not increase plant development. Significant differences in relation to the irrigation levels were found, with better results for the 150% irrigation level compared to 100% evapotranspiration.

Application of chemometric methods in the evaluation of chemical and spectroscopic data on organic matter from Oxisols in sewage sludge applications

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nickel in soil and maize plants grown on an oxisol treated over a long time with sewage sludge

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Barium uptake by maize plants as affected by sewage sludge in a long-term field study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fractionation of Zn, Cd and Pb in a Tropical Soil After Nine-Year Sewage Sludge Applications

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos da aplicação de efluente de tratamento de esgoto na fertilidade do solo e produtividade de pepino sob irrigação subsuperficial

O experimento foi conduzido com o objetivo de avaliar técnicas para a aplicação de águas residuárias na agricultura, proporcionando melhor reutilização de água, recurso natural atualmente escasso e muito mal disponibilizado. Utilizou-se da cultura de pepino (Cucumis sativus L.) em estufa, com oito parcelas irrigadas com efluentes de tratamento de esgoto residencial e oito parcelas irrigadas com água tratada e distribuída pela SABESP (tratamento-testemunha), ambas abastecidas por sistema de irrigação subsuperficial, avaliando-se a produção média por planta, a fertilidade do solo e a disposição de nutrientes na água do solo. Nas análises do solo, verificaram-se maiores teores de P, K e CTC no solo irrigado com efluentes. Nesse mesmo tratamento, constataram-se os maiores teores de N, nitrato, Ca, Mg, Zn e S para as análises da água retida na matriz do solo. Quanto à produção total média por planta, as parcelas irrigadas com efluente apresentaram 2.769,6 g de matéria fresca, superior aos 1.968,6 g verificados no tratamento-testemunha, demonstrando a importância da utilização de efluente de esgoto para o fornecimento de nutrientes e aumento de produtividade.